2003 CHEVROLET AVALANCHE DIC

Engine Air Cleaner/Filter
SeeEngine Compartment
Overview on page 5-12for
location of engine air
cleaner/®lter and change
indicator (if equipped).
When to Inspect
If your vehicle is equipped with a ®lter change indicator
it lets you know when the ®lter needs to be replaced.
Inspect the air cleaner/®lter change indicator every
15,000 miles (25 000 km) and replace the ®lter if
necessary. Vehicles without a change indicator inspect
the air cleaner/®lter every 15,000 miles (25 000 km)
and replace the ®lter every 30,000 miles (50 000 km). If
you are driving in dusty/dirty conditions, inspect the
®lter or change indicator at each engine oil change.
How to Inspect
Locate the ®lter change indicator. When the change
indicator turns black or is in the red/orange ªchangeº
zone, replace the ®lter and reset the indicator. To
inspect the air cleaner/®lter, remove the ®lter from the
vehicle and lightly shake ®lter to release loose dust and
dirt. If the ®lter remains ªcakedº with dirt, a new ®lter
is required.
To inspect and replace the ®lter and reset the indicator
(if equipped), do the following:
The air cleaner/®lter assembly is located on the front
corner of the engine compartment on the passenger's
side of the vehicle.
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Checking Coolant
The coolant surge tank is
located in the engine
compartment on the
passenger's side of the
vehicle.
See
Engine Compartment Overview on page 5-12for
more information on location.
{CAUTION:
Turning the surge tank pressure cap when the
engine and radiator are hot can allow steam
and scalding liquids to blow out and burn you
badly. Never turn the surge tank pressure cap
Ð even a little Ð when the engine and radiator
are hot.
The vehicle must be on a level surface. When your
engine is cold, the coolant level should be at the FULL
COLD mark.
If the LOW COOLANT LEVEL message comes on and
stays on, it means you're low on engine coolant.
See ªLow Coolant Levelº under
DIC Warnings and
Messages on page 3-57.
Adding Coolant
If you need more coolant, add the proper DEX-COOLž
coolant mixtureat the surge tank, but only when the
engine is cool.
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{CAUTION:
You can be burned if you spill coolant on hot
engine parts. Coolant contains ethylene glycol,
and it will burn if the engine parts are hot
enough. Don't spill coolant on a hot engine.
When replacing the pressure cap, make sure it is
hand-tight.
Coolant Surge Tank Pressure Cap
The coolant surge tank pressure cap must be fully
installed on the coolant surge tank. SeeEngine
Compartment Overview on page 5-12for more
information on location.
Notice:Your pressure cap is a pressure-type cap
and must be tightly installed to prevent coolant loss
and possible engine damage from overheating.
See ªCapacities and Speci®cationsº for more
information.
Engine Overheating
You will ®nd a coolant temperature gage on your
vehicle's instrument panel. SeeEngine Coolant
Temperature Gage on page 3-39. In addition, you will
®nd a LOW COOLANT, ENGINE COOLANT HOT,
ENGINE OVERHEATED and a REDUCED ENGINE
POWER message in the DIC on the instrument panel.
See
DIC Warnings and Messages on page 3-57.
Overheated Engine Protection
Operating Mode
If an overheated engine condition exists and the
REDUCED ENGINE POWER message is displayed, an
overheat protection mode which alternates ®ring
groups of cylinders helps prevent engine damage. In
this mode, you will notice a loss in power and engine
performance. This operating mode allows your vehicle to
be driven to a safe place in an emergency. Driving
extended miles (km) and/or towing a trailer in the
overheat protection mode should be avoided.
Notice:After driving in the overheated engine
protection operating mode, to avoid engine damage,
allow the engine to cool before attempting any
repair. The engine oil will be severely degraded.
Repair the cause of coolant loss, change the oil and
reset the oil life system. See ªEngine Oilº in the
Index.
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If No Steam Is Coming From Your
Engine
An overheat warning, along with a low coolant message,
can indicate a serious problem. SeeLow Coolant
Level Warning MessageunderDIC Warnings and
Messages on page 3-57.
If you get an engine overheat warning but see or hear
no steam, the problem may not be too serious.
Sometimes the engine can get a little too hot when you:
·Climb a long hill on a hot day.
·Stop after high-speed driving.
·Idle for long periods in traffic.
·Tow a trailer. SeeTowing a Trailer on page 4-58.
If you get the overheat warning with no sign of steam, try
this for a minute or so:
1. Turn on your heater to full hot at the highest fan
speed and open the window as necessary.
2. If you're in a traffic jam, shift to NEUTRAL (N);
otherwise, shift to the highest gear while driving
± DRIVE (D).If you no longer have the overheat warning, you can
drive. Just to be safe, drive slower for about 10 minutes.
If the warning doesn't come back on, you can drive
normally.
If the warning continues, pull over, stop, and park your
vehicle right away.
If there's still no sign of steam, push down the
accelerator until the engine speed is about twice as fast
as normal idle speed for at least three minutes while
you're parked. If you still have the warning,
turn off the
engine and get everyone out of the vehicleuntil it
cools down. Also, see ªOverheated Engine Protection
Operating Modeº listed previously in this section.
You may decide not to lift the hood but to get service
help right away.
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When to Check Power Steering Fluid
It is not necessary to regularly check power steering ¯uid
unless you suspect there is a leak in the system or
you hear an unusual noise. A ¯uid loss in this system
could indicate a problem. Have the system inspected
and repaired. See
Engine Compartment Overview
on page 5-12for reservoir location.
How to Check Power Steering Fluid
Turn the key off, let the engine compartment cool down,
wipe the cap and the top of the reservoir clean, then
unscrew the cap and wipe the dipstick with a clean rag.
Replace the cap and completely tighten it. Then
remove the cap again and look at the ¯uid level on the
dipstick.
The level should be at the FULL COLD mark. If
necessary, add only enough ¯uid to bring the level up to
the mark.
What to Use
To determine what kind of ¯uid to use, seePart D:
Recommended Fluids and Lubricants on page 6-17.
Always use the proper ¯uid. Failure to use the proper
¯uid can cause leaks and damage hoses and seals. All Other Engines
5-37

Brakes
Brake Fluid
Your brake master cylinder reservoir is ®lled with DOT-3
brake ¯uid. SeeEngine Compartment Overview on
page 5-12for the location of the reservoir.
There are only two reasons why the brake ¯uid level in
the reservoir might go down. The ®rst is that the
brake ¯uid goes down to an acceptable level during
normal brake lining wear. When new linings are put in,
the ¯uid level goes back up. The other reason is
that ¯uid is leaking out of the brake system. If it is, you
should have your brake system ®xed, since a leak
means that sooner or later your brakes won't work well,
or won't work at all.
So, it isn't a good idea to ªtop offº your brake ¯uid.
Adding brake ¯uid won't correct a leak. If you add ¯uid
when your linings are worn, then you'll have too
much ¯uid when you get new brake linings. You should
add (or remove) brake ¯uid, as necessary, only when
work is done on the brake hydraulic system.
{CAUTION:
If you have too much brake ¯uid, it can spill on
the engine. The ¯uid will burn if the engine is
hot enough. You or others could be burned,
and your vehicle could be damaged. Add brake
¯uid only when work is done on the brake
hydraulic system. See ªChecking Brake Fluidº
in this section.
Refer to the Maintenance Schedule to determine when
to check your brake ¯uid. See
Part C: Periodic
MaintenanceInspections on page 6-15.
5-39

Notice:
·Using the wrong ¯uid can badly damage brake
system parts. For example, just a few drops of
mineral-based oil, such as engine oil, in your
brake system can damage brake system
parts so badly that they'll have to be replaced.
Don't let someone put in the wrong kind of ¯uid.
·If you spill brake ¯uid on your vehicle's painted
surfaces, the paint ®nish can be damaged. Be
careful not to spill brake ¯uid on your vehicle. If
you do, wash it off immediately. See
ªAppearance Careº in the Index.
Brake Wear
Your vehicle has four-wheel disc brakes.
Disc brake pads have built-in wear indicators that make
a high-pitched warning sound when the brake pads
are worn and new pads are needed. The sound
may come and go or be heard all the time your vehicle
is moving (except when you are pushing on the
brake pedal ®rmly).
{CAUTION:
The brake wear warning sound means that
soon your brakes won't work well. That could
lead to an accident. When you hear the brake
wear warning sound, have your vehicle
serviced.
Notice:Continuing to drive with worn-out brake
pads could result in costly brake repair.
Some driving conditions or climates may cause a brake
squeal when the brakes are ®rst applied or lightly
applied. This does not mean something is wrong with
your brakes.
Properly torqued wheel nuts are necessary to help
prevent brake pulsation. When tires are rotated, inspect
brake pads for wear and evenly tighten wheel nuts in
the proper sequence to GM torque speci®cations.
Brake linings should always be replaced as complete
axle sets.
See
Brake System Inspection on page 6-16.
5-41

{CAUTION:
Using a match near a battery can cause battery
gas to explode. People have been hurt doing
this, and some have been blinded. Use a
¯ashlight if you need more light.
Be sure the battery has enough water. You
don't need to add water to the ACDelco
ž
battery installed in your new vehicle. But if a
battery has ®ller caps, be sure the right
amount of ¯uid is there. If it is low, add water
to take care of that ®rst. If you don't, explosive
gas could be present.
Battery ¯uid contains acid that can burn you.
Don't get it on you. If you accidentally get it in
your eyes or on your skin, ¯ush the place with
water and get medical help immediately.5. Check that the jumper cables don't have loose or
missing insulation. If they do, you could get a
shock. The vehicles could be damaged too.
Before you connect the cables, here are some
basic things you should know. Positive (+) will go to
positive (+) or to a remote positive terminal (+) if
the vehicle has one. Negative (-) will go to a heavy,
unpainted metal engine part or to a remote
negative (-) terminal, if the vehicle has one.
Don't connect positive (+) to negative (-) or you'll
get a short that would damage the battery and
maybe other parts too.
{CAUTION:
Fans or other moving engine parts can injure
you badly. Keep your hands away from moving
parts once the engine is running.
5-46